@font-family:AvenirNext-Regular,Helvetica Neue,lucida grande,PingFangHK-Light,STHeiti,Heiti SC,Hiragino Sans GB,Microsoft JhengHei,Microsoft Yahei,SimHei,WenQuanYi Micro Hei,Droid Sans,Roboto,Helvetica,Tahoma,Arial,"sans-serif";
.box-sizing{
  box-sizing: border-box;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
}
.left-bar{
&:extend(.box-sizing);
  width:14%;
  height:100%;
  background: #cccccc;

  .el-collapse-item__header{
    background: #cccccc;
  }
  .el-collapse-item__wrap{
    background: #cccccc;
  }
}
